It is desirable to reduce the temperature of chickens and other types of poultry after the birds have been processed, or defeathered, eviscerated and are otherwise oven-ready before the birds are packaged for delivery to the retail customer. A conventional poultry chiller 10, as shown in FIG. 1, is the “auger-type” poultry chiller 10 which includes a trough-shaped, half-round tank 12 filled with cold water in which an auger 20 provides positive movement of the birds through the tank 12. The cooling effect for the water and the birds was originally provided by crushed ice added to the water. As shown in FIG. 2, later designs include a counter-flow recirculation of the chilled water through the tank 12 with the water being chilled by a refrigerated heat exchanger 24 instead of using ice. The water is introduced at one end of the tank 12, the outlet end 16, and flows progressively to the other end, the inlet end 14, where it is recirculated through the heat exchanger 24. In the mean time, the birds are continually delivered to the inlet end 14 of the tank 12 and moved under the influence of the rotating auger 20 in the counter-flow direction and are lifted from the outlet end 16 of the tank 12 for further processing. A prior art poultry chiller of this general type is disclosed in U.S. Pat. No. 5,868,000, and a heat exchanger for the water refrigeration system suitable for this purpose is shown in U.S. Pat. No. 5,509,470.
As noted, chilled water is added to the tank 12 at the outlet end 16, where the birds have been chilled and are being lifted out of the tank 12. The water flows in the opposite direction of movement of the birds and the auger 20 of the tank 12, thereby insuring that the birds are always flowing into the cleanest and coldest water and that there is always a temperature drop between the temperature of each bird and the temperature of the water about each bird.
During operation, the recirculation pump 22 removes the warmer water from the inlet end 14 of the tank 12. As shown in FIG. 2, a suction header 30 connects the inlet of recirculation pump 22 to a sump 26. The sump 26 is positioned at an overflow recess in the sidewall of the chiller tank 12 and is below the typical operational water level within the tank 12. A typical sump can measure about 4 feet high and from 2 to 4 feet in width. The sump 26 helps to insure that the inlet of the suction header 30 does not become blocked by birds in the tank and that adequate chill water is present for the recirculation pump 22 to maintain proper suction. A suction valve 42 is disposed in the suction header 30 in close proximity to the sump 26. The outlet of recirculation pump 22 discharges the chill water into a fill header 32 that includes a heat exchanger 24 for chilling the water. After having passed through the heat exchanger 24, the chill water continues down the fill header 32 and enters the tank 12 at the outlet end 16. A fill valve 44 is disposed in the fill header in close proximity to the tank 12.
Side mounted sumps, such as the sump 26, tend to cause operational problems in typical chillers 10. For example, although the warmer water side discharge opening in the wall of tank 12 that is in fluid communication with the side mounted sump 26 is typically rather large, and the sump is approximately 2 to 4 feet wide and 4 feet tall, it is possible for birds to migrate to this portion of the tank 12 wall and be sucked up against the edge of the opening without passing through the opening. If enough birds migrate to the opening into the side mounted sump 26, partial blockage of the access of recirculation water to the suction header 30 can occur. In turn, the performance of the recirculation pump 22 is affected in that chill water flow rate throughout the poultry chiller 10 is reduced. Eventually, the birds will be urged away from the opening to the side mounted sump 26 by the outer periphery of an oncoming flight of the auger 20. However, because full 360° flights on typical augers 20 are frequently longitudinally displaced by 4 feet or more and the auger 20 rotated on the order of 1 turn every 4 minutes, the birds partially blocking the side mounted sump 26 inlet can remain there for extended periods of time prior to being displaced and the reduced flow of recirculation water continues.
Also, as previously noted, the chill water becomes progressively warmer as it moves from the outlet end 16 to the inlet end 14 of the tank 12. Generally, the temperature of the water in front of a flight is colder than the water behind the flight, as much as 2° F. As the auger 20 rotates, the last auger flight funnels water into the side mounted sump 26 sometimes from in front of the flight and other times from behind the flight as the flight passes by the warmer water side discharge opening. This means that when the individual flight 20A funnels water into the side mounted sump primarily from behind the individual flight 20A, the inlet temperature of chill water at the heat exchanger 24 will be warmer than when the majority of water funneled into the side mounted sump 26 is from in front of the individual flight 20A. These temperature variations mean that frequent adjustments must be made to the heat exchanger 24 to maintain a constant chill water temperature in the fill header 32.
To maintain proper sanitary conditions, poultry chillers 10 typically are cleaned on a daily basis. As shown in FIG. 2, prior art poultry chillers 10 include a clean-up tank 28 that holds cleaning solution that is used for cleaning the chill water circulation system of the poultry chiller 10 during shut down of the chiller. Usually, the clean-up tank 28 can be mounted either to the side of the poultry chiller 10 in a manner similar to that of the sump 26, or it may be free standing. Clean-up tanks 28 typically are on the order of 300 to 500 gallons and are connected to the chill water system by a recirculation header 34 and control valves 46 and 48. As shown in FIG. 2, a first portion 34a of the recirculation header 34 taps into the suction header 30 between the suction valve 42 and the recirculation pump 22. A recirculation suction valve 46 is used to either line up or isolate the clean-up tank 28 from the suction header 30. A second portion 34b of the recirculation header 34 taps into the fill header 32 upstream of the fill valve 44 and includes the recirculation fill valve 48 that can be used to either line up or isolate the clean-up tank 28 from the fill header 32.
To clean the poultry chiller 10, the tank 12 is drained of water and birds and cleaning personnel clean the auger 20 and the inside of the tank 12 with hot water and cleaning solution under high pressure. The chill water system is cleaned by shutting the suction valve 42 and the fill valve 44 to isolate the chill water system from the tank 12. A mixture of cleaning solution and hot water is mixed in the clean-up tank 28 by cleaning personnel. The clean-up tank 28 is then aligned with the chill water system by opening the recirculation suction valve 46 and the recirculation fill valve 48. The recirculation pump 22 is now aligned to take suction off the clean-up tank 28, thereby pumping the solution of hot water and cleaning solution through the suction header 30, recirculation pump 22, heat exchanger 24, fill header 32, and the recirculation header 34. Note however, the portion of the suction header 30 disposed between the suction valve 42 and the side mounted sump 26, indicated by reference numeral 50, is not cleaned during recirculation of the cleaning solution from the clean-up tank 28. As such, this portion of the suction header 30 must be cleaned by cleaning personnel, as is the side mounted sump 26.
A number of problems are common to the side mounted sump 26 and the clean-up tank 28 when the clean-up tank 28 is mounted directly to the side of the tank 12. When mounted to the side of the tank 12, the sump 26 and clean-up tank 28 interfere with the routine of the cleaning personnel, and take up space along the side of the poultry chiller 10 which is frequently at a premium. Also, side-mounting the sump 26 and clean-up tank 28 can interfere with the placement of a cat walk (not shown) along the upper edge of the tank 12, as is common in the manufacture of poultry chillers 10. Also, manufacturing the sump 26 and the clean-up tank 28 adds to the overall cost of producing the poultry chiller 10 in that the construction of the typically rectangular boxes requires significant man hours. Additionally, because the clean-up tank 28 is independent of the sump 26, the suction portion 34A of the recirculation header 34 and the recirculation inlet valve 46 are required. If a single tank were used that served both functions, a common portion of suction piping and a single isolation valve could be used.
From the foregoing, it can be appreciated that it would be desirable to have an integral sump compartment for use for with the poultry chiller that can function as both a sump for the recirculation pump suction and as a clean-up tank. Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.